The present invention concerns a chucking device which includes a lever operated hydraulically or pneumatically by a piston for chucking pieces to machine or to weld.
In the industrial domain, and particularly in the automobile industry, it is necessary to hold the pieces, for example, in order to machine them or to attach them by welding. One has recourse, of course, has different devices, like for example a joining plane or a system of levers, maneuvered manually, which presents a certain number of inconveniences. Also, having perfected the system of automatic clamping that includes, at least, a lever that changes to an inactive position of release from an active position of clamping, and inversely by the movement of a piston controlled either pneumatically or hydraulically.
One knows many clamping devices that include a fluid cylinder controlling the movement of the lever arm directly or by an intermediary system of a connecting rod and crank. These clamping devices operate between two positions, the first one, the inactive position, releases the piece; the second, the active position, clamps onto the piece.
These devices, in a known way, are contained in a case formed by two half-shells of mirror symmetry along their joining plane.
This type of case is subjected to great mechanical pressures, notably at the time of clamping, thus, the two half-shells are made of a material resistant to deformation, torsion, traction, or compression.
That is why the chosen materials are often aluminum or steel.
The inconvenience in using these materials lies in the fact that they are expensive and heavy.
Furthermore, such a case will have to be painted or treated, in order to withstand the external pressure that occurs, for instance, during the discharge while welding a piece.
According to the first phase of the invention, the case has to effectively offer resistance to the mechanical constraints, but this does not concern the whole case, only certain unique zones.